Nitrate Content in Potatoes Cultivated in Contaminated Groundwater Areas

Abstract

For a number of years Dravsko polje plain has been subject to intensive farming. Consequently, groundwater in this area is heavily contaminated with nitrates and pesticides. The goal of the study was to determine the quality of potatoes, based on nitrate levels cultivated in an area of contaminated groundwater. We also examined the influence of sustainable agriculture on the quality of crops. Nitrate content was determined using RP/HPLC/UV chromatography. Average nitrate content in potatoes cultivated on Dravsko polje plain was 157 mg/kg (range 18-429 mg/kg), which was not significantly different from the nitrate content in potatoes cultivated outside the contaminated area (mean value 145 mg/kg; range 28-448 mg/kg). In 18% of all samples, nitrate content exceeded maximum recommended levels. In potatoes cultivated via integrated production nitrate content did not significantly differ from the one in conventionally cultivated potatoes. In contrast, organic potatoes contained lower levels of nitrates (range 14-156 mg/kg). Our results also show that individual potato varieties are characterized by different trends of nitrate accumulation. Strict adherence to sustainable agriculture is reflected in lower levels of nitrate in potatoes.

Effect of Urea Fertilizer and Poultry Manure on Nitrate Reductase Activity of Potato and some Tuber Composition

“…10,33 However, some researchers have considered the role of genetics in nitrate accumulation more important and believe that the differences are more dependent on the capacity of the cultivars in the accumulation of nitrates. 9 It is known that organic fertilizers with slowly or moderately available nitrogen compared with chemical ones lead to lower nitrate accumulations in vegetables. 19 No sample from both nitrogen sources exceeded, however, the nitrate limit of 200 mg.kg −1 FW was proposed by some European countries, which is an important benefit in the context of human health.…”

“…8 It has been reported that 97% of nitrate entries the human body through vegetables, 32% of which is the contribution of potato consumption. 9 The acceptable daily intake (ADI) of nitrate ion is 3.65 mg kg -1 body weight (equivalent to 219 mg.day -1 for a person weighing 60 kg) based on the European Commission (EC)'s and Scientific Committee for Food (SCF). 10 The accumulation rate of nitrate in potato tubers, in addition to the genetic factor, is attributed to other factors such as light intensity, growth season temperature, pest and disease control methods and soil moisture.…”

“…10 The accumulation rate of nitrate in potato tubers, in addition to the genetic factor, is attributed to other factors such as light intensity, growth season temperature, pest and disease control methods and soil moisture. 9,11 The response of a plant to nitrate accumulation is depended on nitrate reductase (NR) enzyme activity and other metabolic reactions mainly related to nitrate. Also, the NR activity is related to the amount of nitrate sensitive protein production.…”

Monitoring of Nitrate Content in Potatous From Bulgarian Market

“…Potato is an important and popular food in the EU, average of 73 kg kg/capita/year. The highest consumption per person per year is in Latvia -178 kg, followed by Poland -118 kg, and Greece 103 kg [5]. Global potato consumption in 2013 was on average 35 kg/capita/year, which is about 50% of the world's food energy needs [6].…”

“…Global potato consumption in 2013 was on average 35 kg/capita/year, which is about 50% of the world's food energy needs [6]. Potatoes can be the main source of nitrate intake [5]. According to Santamaria [7], vegetables account for 97% of our nitrate intake, as 32% originates from potato consumption and 29% from lettuce consumption.…”